DESCRIPTION: This study proposes to conduct a prospective follow up of the experiences and attitudes of individuals who participated in the Ashkenazi supplement to the Cooperative Family Registry of Breast Cancer Families (CFRBCS) during the period of 1997-2000. As part of an international cooperative study, we have the unique opportunity to compare issues of genetic testing for breast cancer susceptibility in a diverse group representing different health care systems, cultural attitudes, and laws protecting privacy of genetic information. The objectives of the proposed study are to describe the characterstics of individuals who accept genetic testing for breast cancer and to study the sequelae of genetic testing over a follow-up period of up to eight years The study population will consist of 828 Ashkenazi Jewish individuals who participated in psychosocial studies conducted through the four Ashkenazi supplemental awards to the CFRBCS. In addition, newly recruited individuals ascertained through high-risk clinics and population based methods at five sites during the current proposal who are contemplating genetic counseling and testing will also be invited to participate (projected new recruitment over five years=1250 individuals, total sample size=2078). The psychosocial data obtained at baseline at each of the sites (Mount Sinai School of Medicine, New York, Fox Chase Cancer Center, Cancer Care Center, Ontario, Sydney, Australia, Northern California Cancer Center) will be analyzed to provide a description of the individuals who chose testing. For the long-term follow up studies, standardized measures as well as a questionnaire developed by the research team using the results of focus groups, will be administered to assess retention of knowledge, anxiety and distress, intrusive thoughts, self-and societal-stigmatization, issues of privacy, including disclosure of results, experiences of discrimination either in employment or insurance, and patterns of medical follow-up in relation to cancer surveillance and treatment behaviors. Importantly, attitudes toward genetic testing in general and predicted acceptance of future genetic testing for modifier genes or other breast cancer susceptibility genes will be measured. It is anticipated that during the course of this five-year study, genetic testing for newly identified modifier genes or cancer susceptibility genes will be introduced. We will then have the unique opportunity to determine actual testing uptake in this group and to determine predictors of acceptance of genetic testing. This will provide valuable information that can be used in future intervention studies to assist health care professionals in genetic counseling and individuals in their decision-making. Finally, the opportunity to compare the attitudes and outcomes of individuals who accepted genetic testing and counseling, but who come from diverse geographical areas with different systems of health care should provide important information to benefit the general population.